Aspergillus Fumigatus Conidia Induce Ifn-Beta Signaling In Respiratory Epithelial Cells

R. Bals , C. Beisswenger

Author address: 

Department of Internal Medicine V, Homburg/Saar, Germany

Abstract: 

Aspergillus fumigatus is a fungal pathogen of major clinical importance. However, little is known about the role of human bronchial epithelial cells (HBEC) during A. fumigatus conidia induced inflammation. Here we show that differentiated respiratory epithelial cells recognize resting but not swollen conidia or hyphae resulting in the induction of the IFN-β signaling pathway and the expression of IFN-β inducible genes such as IP-10. This induction was internalization dependent. We identified double stranded conidia RNA recognized by TLR-3 as a factor responsible for the expression of IFN-β and IP-10. Inhibition of RIP-1/TBK-1, known to mediate IFN-β signalling, was sufficient to inhibit the induction of IFN-β and IP-10 expression by conidia. Even though resting conidia induced the activation of NF-954;B in HBECs, IP-10 expression was only partially dependent on NF-954;B signalling. These results provide evidence that respiratory cells are activated by double stranded RNA of resting conidia and initiate a first immune response to inhaled conidia in an IFN-β dependent manner.
2011

abstract No: 

A65

Full conference title: 

American Thoracic Society
    • ATS 2011